The Bitcoin Foundation released their January 2015 report on their development efforts today. Among other accomplishments was iterating the version number of their reference implementation of the Bitcoin protocol to version 0.5.3.1 and subjecting it to further rigor.
Much progress was made by the foundation and collaborators on identifying mapOrphanBlocks as the major culprit behind the memory exhaustion fault and crashes during initial synchronization. A substantial amount of time, testing, and memory profiling has gone into this discovery and a number of remedies are being explored. In the interest of the reference implementation being a robust solution that requires minimal trust of its peers, the block headers only approach favored by the Vessenes' foundation's forks' developers is being passed over in favor of actual solutions.
A side project that has served as a fruitful ground for testing the Foundation's codebase has been in testing the code on common sub twenty dollar ArmV5 based Pogoplug hardware. The hoped for end goal of the project is a reproducible way for adding new Bitcoin nodes to the network in order to resist attacks by hostile entities at a minimal cost. Practically though the effort is resulting in a substantial amount of testing this Bitcoin implementation on resource constrained hardware in a way that may help to illuminate what the minimum viable hardware is for a functional Bitcoin full node.
The foundation is also working on a portable script patching and building binaries from source to assist in regression testing. If regression testing is passed the Foundation tentatively aims to make a release their code as a reference implementation sometime in February, barring too many roadblocks.